Losing network connection after each Proxmox reboot

[Ademantis]

As per title, everytime I reboot proxmox I am losing network connection and access to the GUI. Any idea if anyone had this before and how to solve this?

Did run a

ifup vmbr0
error: vmbr0: bridge port enp4s0 does not exist

#etc/network/interfaces

auto lo
iface lo inet loopback

auto enp4s0

iface enp4s0 inet manual

auto vmbr0
iface vmbr0 inet static
    address 192.168.0.11/24
    gateway 192.168.0.1
    bridge-ports enp4s0
    bridge-stp off
    bridge-fd 0

iface wlp3s0 inet manual

this was working fine before I rebooted

Note: Did find the solution. The enp4s0 changed to enp3s0 for some unknow reason after reboot. Anyone can explain why?

How i fixed it, in case anyone have this issue, run:

ls /sys/class/net

should show the enpXXXs0, change it accordingly in your etc/network/interfaces file

 

[Stoiko Ivanov]

This happens every now and then and is dependent on the BIOS/Motherboard and its pci-device enumeration.
(it's a result of systemd's predictable network interface names) - see e.g.:
https://forum.proxmox.com/threads/latest-systemd-udev-breaks-network-device-naming.53238
and
https://forum.proxmox.com/threads/webui-unreachable-after-adding-nvme-drive.85500

put shortly - usually after you've fixed it it should stay stable (until the next BIOS update or major kernel update)

I hope this helps!